XJ's have coil fronts, leaf rears. TJ coils are designed to work with a vehicle that weighs in excess of 3,200 pounds, so my guess is they'd be a little stiff. How much you want for them though, the wife has a TJ and we might use the coils later on when hers sag. Are they off a 4 cyl or 6 cyl and are they designed for use with the hard top?
The YJ's have a set of swaybars front and rear, so this would be a good place to start for stability. Incidentally, the TJ is very stable with the swaybars connected. With the front disconnected, it has noticeable body roll, but is still controllable. With the rear disconnected it's a death trap over 10 mph, completely unpredictable and impossible to drive. Ramp travel numbers for a 23 degree ramp are: 330 stock, 490 front disconnected, 495 front and rear disconnected, so the rear actually does little for travel.
JEEPN
Winter Harbor, Maine
'81 CJ-8 Scrambled!
It's a Jeep, Chevy, IHC kinda thing!